Pad slitter

ABSTRACT

A slitter for gang severing of the glued edge of a bulk size pad of paper, to divide it into several thinner pads. An unglued face surface of the pad is aligned against a fixed guide and is pressed toward the fixed guide while a cutter holder is moved relative to the pad in a plane parallel to the glued edge. A blade lying parallel to the sheets of paper in the pad is oriented a predetermined distance from the guide, and projects through the glued edge so as to sever the latter without cutting the paper itself.

United States Patent [191 Deutsch [451 June 25, 1974 PAD SLITTER [76] Inventor: Howard Deutsch, 2444 Madison Rd., Cincinnati, Ohio 19452 [22] Filed: Jan. 4, 1973 [21] Appl. No.: 320,921

[52] US. Cl. 83/7, 83/11 [51] Int. Cl B26d 3/08 [58] Field of Search 83/6, 11, 12, 425.1, 425.2,

[56] References Cited UNITED STATES PATENTS 1,919,964 7/1933 Spang s3/425.1 x 2,150,735 3/1939 Williams 83/4252 2,323,760 7/1943 Wolfinger, Sr 83/4252 3,154,124 10/1964 Cimino ..83/425.2X

Primary Examiner-Willie G. Abercrombie Attorney, Agent, or FirmWood, Herron & Evans [57] ABSTRACT A slitter for gang severing of the glued edge of a bulk size pad of paper, to divide it into several thinner pads. An unglued face surface of the pad is aligned against a fixed guide and is pressed toward the fixed guide while a cutter holder is moved relative to the pad in a plane parallel to the glued edge. A blade lying parallel to the sheets of paper in the pad is oriented a predetermined distance from the guide, and projects through the glued edge so as to sever the latter without cutting the paper itself.

8 Claims, 4 Drawing Figures PAD SLITTER This invention relates to a pad slitter, which is an apparatus for severing the glued edge of a pad of a large number of sheets of paper, so as to separate the bulk pad into thinner pads of accurately predetermined thickness.

The slitter is especially useful in the manufacture of unbacked pads, for example pads of marketing premiums of the type that are widely used in supermarkets. Such pads do not have a cardboard or other backing, and in general comprise a number of identical printed sheets or pages. The sheets are adhered to one another for sequential tear-off removal by a so-called padding glue, which is typically a tearable, flexible rubberized cement that is coated across one edge of the stack of sheets. The pads are usually made up in bulk from a large number of sheets, and the glued edge of the resulting bulk pad is then slit to form smaller (i.e., thinner) pads, each containing a desired number of sheets.

In the past, the slitting or pad cutting operation has been carried out manually. In order to locate the places at which the glued edge of the bulk pad should be severed to form the smaller pads, in one prior technique the printed sheets have been stacked with colored marker sheets inserted at predetennined positions. For example, where a pad is to consist of 50 sheets, the bulk pad-which might contain 1,000 sheets--is assembled with colored marker pages after the 50th, 100th, l50th, etc. printed pages. After the bulk pad has been glued, a worker would then sever the glued edge at the position indicated by the marker sheets. To do this, he located the first marker sheet, inserted a knife blade at that sheet, cut through the glued edge, tore off the marker sheet and threw it away, and then repeated the operation at each of the other marker sheets. That manual technique is relatively slow in that it requires the proper insertion of the marker sheets before glue up, then relocating them and cutting the pad at those positions, and tearing off the markers. Moreover, it is expensive in that the marker sheets are wasted; where a marker is inserted, say, every 50 or 100 pages, this becomes a significant extra paper cost. The slitting must be done at the proper position, in order to form pads with standardized numbers of sheets. This is especially important where close control over the number of premiums is necessary.

Another previous technique used to identify slitting locations is known as spooning. According to that procedure, a reference surface was pressed down on the top of the bulk pad while a separator or spoon, spaced a fixed distance below the reference surface, was slipped between the sheets to locate the thickness where the slit was to be made. This also was a timeconsuming, manual technique, and the number of pages of the resulting pad varied because different workers exerted different hold down pressures on the reference surface.

The cost of manufacturing pads must of course be held to a minimum. It has, therefore, been desirable to provide an apparatus for bulk pad cutting whereby manual handling is reduced to the minimum, expense is reduced, and better page count accuracy is achieved.

Various types of devices are of course known for gang sawing, see for example Marston U.S. Pat. No.

186,742, which relates to the gang sawing of logs. Devices for trimming the edges of pads to size are also known, as shown in Taylor U.S. Pat. No. 758,156; as is apparatus for slitting sheet material to form long strips, as shown in U.S. Pat. No. 2,409,203. However, there has not previously been any mechanized device for severing a glued edge of a bulk pad to form separate pads, without cutting or marring the paper comprising the pad.

In accordance with the invention, a pad slitter is provided which includes a fixed guide for supporting one surfacenot the glued edge-of a bulk pad. Biasing means are spaced from this guide but parallel to it, and in use they urge the pad toward the guide. A cutter holder presents at least one cutter blade which has a cutting edge positioned to project in use through the glued edge of a pad whose large surfaces (in contradistinction to its edges) are supported by and between the guide and the biasing means. The invention also includes means for establishing relative motion between the cutter blade and the pad, in a direction parallel to the sheets of the pad, thereby to cause the cutter blade .to sever the glued edge. In preferred embodiment, the

relative motion establishing means comprise drive means for engaging the pad and moving it past the cutter blade, in the form of a pair of oppositely arranged, synchronized endless belts for respectively engaging the opposite surfaces of the pad, one belt moving over the laterally fixed guide and the other belt moving over the biasing means so that the pad is captured between them.

The invention can best be further described and explained by reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a preferred embodiment of pad slitter apparatus in accordance with the invention, and shows a pad positioned to be moved through the apparatus;

FIG. 2 is a top plan view of the cutter holder assembly, and illustrates the position of the staggered and longitudinally spaced cutter blades;

FIG. 3 is a fragmentary section taken on line 3-3 of FIG. 2, and shows the cutter holding means, and

FIG. 4 is a horizontal section taken on line 44 of FIG. 3, showing the manner in which the blades engage and slit the glued edge as the pad is carried past them.

The preferred form of apparatus shown in FIG. 1 is mounted on a bench or table generally at 10, having a flat pad supporting work surface 11. A vertically oriented frame edge 12 is mounted at the perimeter of surface 1 l, and provides a support against which a pad can be oriented before it is passed through the slitter itself which is indicated generally at 13.

Slitter 13 includes a vertically positioned generally planar guide or plate 18 which is carried on a back-up plate 19 that is mounted to brackets or angles 20. Guide 18 is preferably made with a material having a low coefficient of friction such as Teflon, and is fixed in its lateral position with respect to the table.

A biasing means in the form of a guide or plate 24 is positioned parallel to guide 18, but is spaced laterally from the latter by slightly less than the width of the pad that is to be cut. Like plate 18, plate 24 may be made of low friction material. Plate 24 is supported and mounted on a back-up plate 25, which is urged by springs 26 toward guide 18 and which has a range of movement toward and away from guide 18. The springs 26 are mounted from spring support brackets 27.

In FIG. 1, a bulk pad 30 is shown positioned on table surface 11, oriented for being passed through the slitter. Pad 30 has opposite face surfaces 31 and 32 and a glued edge 33. The pad is oriented for slitting with one surface 31 proximate to guide 18. Guide 24 engages the other or opposite surface 32 of pad 30, and urges the pad toward guide 18 which thus functions as an alignment surface. The gluded edge 33 of the pad resides in a plane which is perpendicular to the planes of the guides 18 and 24.

The pad 30 is moved through the slitter by drive means which establish relative motion between the pad and the actual cutter blades. Preferably these drive means comprise two endless belts, designated at 36 and 37, which engage the opposite unglued pad surfaces 31 and 32, inwardly of guides 18 and 24 respectively. Belt 36 extends around end rolls 40 and 41 and a tensioning roll 42. One of the end rolls is driven by a motor, not shown. The belt 36 engages surface 31 of the pad, and moves over the low friction guide 18. The other belt 37 passes around end rolls 43 and 44, one of which is a driven roll and moves in synchronism with the other driven roll so that both belts move at the same speed. (For this purpose the rolls may be connected by a synchronizing belt beneath table 11, not shown.) Belt 37 moves over the low friction pad 24 and engages surface 32 of pad 30. A suitable stop-start and/or motor speed control 46 may be provided for motor operation. Belt 37 is held taut by tensioning roll 45.

The cutter blade assembly or holder is designated generally at 50 and presents a series of individual cutter blades 51 (see FIG. 3), each having a cutting edge 52 that projects so that in use it will slit the glued pad edge 33. Preferably the cutter blade edge 52 does not project so far as to extend substantially below the glued edge, between the unglued sheets. A cutter depth of about one-eighth inch below the upper surface of the glued edge 33 has been found to work well for this purpose.

The individual cutter blades 51 may for example comprise sharpened slitter knife blades of known type, which are generally trapezoidal in shape and reversible end for end. Such blades have a mounting notch 54 in the edge thereof which is opposite to the cutting edge 52. Each cutter blade 51 is clamped between spacer means comprising two steel bars 56 which are notched or relieved by a cross-slot 57 (see FIG. 2) to accommodate the thickness of the blade.

The cutter blades 51 are preferably arranged in several rows which are spaced longitudinally, i.e., in the direction of relative pad movement. The reason for this is that each blade has a small but definite thickness which, as the blade passes between adjacent sheets of paper, slightly separates the sheets and forces them transversely outwardly. The total width of several cutter blades is not negligible, and may total several sixteenths of an inch. In order to accommodate this lateral deflection of the paper as the blades cut the glue, and to prevent jamming, marking, or tearing of the paper that could otherwise result if the bulk pad comprises on the order of l,000 sheets, preferably no more than about five blades are in a single row. In the embodiment shown, the blades 51 are arranged in four rows, designated as 58 A, B, C, and D. Row 58 A contains four cutter blades, and each of rows 58 B, C, and D contains five cutter blades. The blades are staggered and are spaced apart laterally by distances such that they will slit the bulk pad 30 into smaller pads of desired thickness. The actual pad page count will of course vary from case to case, but often is 50 sheets. In a typical instance, pad 30 is made up of 1,000 sheets of paper, and is slit into 20 separate pads by the 19 cutter blades, each smaller pad comprising 50 sheets.

Each cutter blade 51 is secured in its cross-slot 57 by means of a stud or pin 59 which is engaged in notch 54 of the blade. The mounting bars 56 are clamped together by bolts 60 and 61 which pass through openings in them, so that the cutter blades are held in ganged relationship to form the assembly 50. Outer or backing bars 63 and 64, through which bolts 60 and 61 also project, are mounted to support brackets 65 on table 11.

As shown in FIG. 1, cross-bars 68 and 69 extend transversely across cutter assembly 50 and are fastened to the top of backing bars 63 and 64. These are slotted, as at 70, and can be shifted laterally on bolts 71 which pass through the slots and are fastened to threaded sleeves 72. This transverse shiftability permits the cutter assembly 50 to be oriented so that the cutter blades are precisely parallel to and between the sheets of the pad, so that as the pad is carried past the blades the blades do not cut or mar the sheets. The proper height of the blades with respect to work surface 11 is adjustable by use of stop nuts or bolts 71.

In order to accommodate the previously mentioned transverse shifting of the sheets as the pad sequentially passes the rows 58 A-D of cutter blades, the surfaces of guides 18 and 24 are relieved by recesses 67 formed therein in line with the rows 58 (see FIG. 4). These recesses provide sufficient sidewise expansion room for the paper, and belts 36 and 37 as they move past, to prevent jamming.

In the operation of the slitter, a glued pad 30, which is to be severed into a plurality of pads of lesser thickness, is placed on the table 11 against the support edge 12 thereof. Control 46 is actuated to start the belts 36 and 37 moving in the direction indicated by the arrow, and the pad is advanced (toward the upper left, with reference to FIG. 1) until its leading edge 75 is caught in the nip between belts 36 and 37. As the belts engage the opposite surfaces 31 and 32 of the pad, they advance the pad through the space between guides 18 and 24, and the springs 26 acting through guide 24 urge the pad toward guide 18 which accurately prealigns it with respect to the cutter assembly 50. The pad is first slit by the four cutters in row 58A, which split it into four smaller pads. As the pad continues to be advanced it is then slit by the five cutter blades in row 583, then by the blades in rows 58C, and finally those in row 58D. At the end of its passage through the cutter it has been slit into the desired number of separate pads. If appropriate, the separate pads may then be transferred to a separate device of known type for cutting them to size (i.e., cutting perpendicular to the sheets).

In the embodiment described, the pad 30 to be cut is moved relative to the blades by the belts 36 and 37 which advance it past them. However, from the foregoing description those skilled in the art will appreciate that such relative motion could also be achieved by holding the pad stationary and moving the cutter assembly lengthwise over the glued edge. A cutter mechanism which is reciprocable on guide ways is contemplated as an alternative for this purpose.

in the embodiment described, the glued edge 33 to be cut is disposed in a horizontal plane, and the pad is supported on table surface 11. Those skilled in the art will appreciate that the cutter assembly 50 could in effect be rotated 90, with the glued edge 33 in a vertical alignment, such that the pad surface 31 rests on support surface 12.

I claim:

1. A pad slitter for separating a bulk sheet pad into a plurality of thinner sheet pads, said bulk sheet pad having two opposed planar face surfaces and being made of separate sheets held together at a glued edge perpendicular to said two face surfaces, said slitter comprising,

a first guide for locating one face surface of a bulk pad in a fixed predetermined plane,

a second guide spaced from and parallel to said first guide for engaging the opposite face surface of the pad, said second guide being movable in the direction toward and away from the first guide,

a cutter blade assembly including at least one cutter blade having a cutting edge, said assembly positioned so that said edge will in use project through the glued edge of said bulk sheet pad but not substantially beyond that glued edge into the pads interior, thereby to slit only said glued edge,

biasing means connected to said second guide, said biasing means urging said second guide in said direction toward said first guide for restraining said pad therebetween for prealigning said pad relative to said cutter blade,

and means for establishing relative motion between said cutter blade and said bulk pad in a direction parallel to the sheets of said pad so that said blade severs said glued edge, thereby forming a plurality of smaller pads each of a predetermined thickness.

2. The pad slitter of claim 1 which further includes a work surface for engaging an unglued edge of said pad,

said first and said second guide each residing in a vertical plane above said work surface.

3. The pad slitter of claim 1 wherein said means for establishing relative motion comprises a pair of oppositely arranged synchronized endless belts for respectively engaging the two opposed planar face surfaces of said pad, one belt moving over said first guide and the other belt moving over said second guide.

4. The pad slitter of claim 1 which includes a plurality of cutter blades,

and cutter blade spacer means which hold the blades uniformly spaced apart to cut smaller pads with equal thicknesses.

5. The pad slitter of claim 4 which includes a plurality of rows of cutter blades, said rows being spaced apart in the direction of the relative motion to sever said glued edge at different positions.

6. The pad slitter of claim 1 wherein said first guide and said second guide are each essentially planar and are recessed at positions corresponding to the longitudinal positions of each cutter blade, thereby to accommodate lateral movement of the pad in response to the width of the cutter blade as the pad transverses it.

7. The pad slitter of claim 1 which further includes means for adjusting the transverse alignment of said cutter blade assembly with respect to said first guide.

8. A method of separating a bulk sheet pad into a plurality of thinner sheet pads, said bulk sheet pad and said thinner sheet pads each being made of separate sheets held together at a single glued edge, comprising the steps of:

supporting the bulk pad so that the glued edge is exposed for slitting;

supporting a plurality of cutter blades in laterally parallel spaced relation according to the thicknesses desired of the thinner sheet pads,

positioning the blades to project in use through said glued edge into the pad but not substantially beyond that glued edge into the pads interior for slitting said glued edge only,

moving the pad relative to the blades in a direction parallel to the pad sheets so that the blades slit the glued edge of the pad, thereby forming a plurality of smaller pads each of a predetermined thickness. 

1. A pad slitter for separating a bulk sheet pad into a plurality of thinner sheet pads, said bulk sheet pad having two opposed planar face surfaces and being made of separate sheets held together at a glued edge perpendicular to said two face surfaces, said slitter comprising, a first guide for locating one face surface of a bulk pad in a fixed predetermined plane, a second guide spaced from and parallel to said first guide for engaging the opposite face surface of the pad, said second guide being movable in the direction toward and away from the first guide, a cutter blade assembly including at least one cutter blade having a cutting edge, said assembly posiTioned so that said edge will in use project through the glued edge of said bulk sheet pad but not substantially beyond that glued edge into the pad''s interior, thereby to slit only said glued edge, biasing means connected to said second guide, said biasing means urging said second guide in said direction toward said first guide for restraining said pad therebetween for prealigning said pad relative to said cutter blade, and means for establishing relative motion between said cutter blade and said bulk pad in a direction parallel to the sheets of said pad so that said blade severs said glued edge, thereby forming a plurality of smaller pads each of a predetermined thickness.
 2. The pad slitter of claim 1 which further includes a work surface for engaging an unglued edge of said pad, said first and said second guide each residing in a vertical plane above said work surface.
 3. The pad slitter of claim 1 wherein said means for establishing relative motion comprises a pair of oppositely arranged synchronized endless belts for respectively engaging the two opposed planar face surfaces of said pad, one belt moving over said first guide and the other belt moving over said second guide.
 4. The pad slitter of claim 1 which includes a plurality of cutter blades, and cutter blade spacer means which hold the blades uniformly spaced apart to cut smaller pads with equal thicknesses.
 5. The pad slitter of claim 4 which includes a plurality of rows of cutter blades, said rows being spaced apart in the direction of the relative motion to sever said glued edge at different positions.
 6. The pad slitter of claim 1 wherein said first guide and said second guide are each essentially planar and are recessed at positions corresponding to the longitudinal positions of each cutter blade, thereby to accommodate lateral movement of the pad in response to the width of the cutter blade as the pad transverses it.
 7. The pad slitter of claim 1 which further includes means for adjusting the transverse alignment of said cutter blade assembly with respect to said first guide.
 8. A method of separating a bulk sheet pad into a plurality of thinner sheet pads, said bulk sheet pad and said thinner sheet pads each being made of separate sheets held together at a single glued edge, comprising the steps of: supporting the bulk pad so that the glued edge is exposed for slitting; supporting a plurality of cutter blades in laterally parallel spaced relation according to the thicknesses desired of the thinner sheet pads, positioning the blades to project in use through said glued edge into the pad but not substantially beyond that glued edge into the pad''s interior for slitting said glued edge only, moving the pad relative to the blades in a direction parallel to the pad sheets so that the blades slit the glued edge of the pad, thereby forming a plurality of smaller pads each of a predetermined thickness. 